As circuit board densities and clock speeds increase, the electromagnetic fields between signals routed on a printed circuit board interfere with signals transmitted on nearby leads. This cross-talk increases the signal to noise ratio of the signals, which in turn lessons the ability of different circuit components to communicate with each other.
One technique that has been used to reduce cross-talk between traces on a printed circuit board is to place ground planes in one or more areas and/or different layers of the printed circuit board. These ground planes may be connected with one or more grounding vias, (i.e., small conductive tunnels that extend though the various layers of the printed circuit board). While the ground planes and ground vias do aid in reducing cross-talk between the signal traces, it is desirable to further reduce cross-talk whenever possible.